The crucial relationship between miRNA-27 and CSE/H2S, and the mechanism of action of GLP-1 in myocardial hypertrophy.

Cardiac hypertrophy is the most prevalent compensatory heart disease that ultimately leads to spontaneous heart failure. Mounting evidence suggests that microRNAs (miRs) and endogenous hydrogen sulfide (H2S) play a crucial role in the regulation of cardiac hypertrophy. In this study, we aimed to investigate whether inhibition of miR-27a could protect against cardiac hypertrophy by modulating H2S signaling. We established a model of cardiac hypertrophy by obtaining hypertrophic tissue from mice subjected to transverse aortic constriction (TAC) and from cells treated with angiotensin-II. Molecular alterations in the myocardium were quantified using quantitative real time PCR (qRT-PCR), Western blotting, and ELISA. Morphological changes were characterized by hematoxylin and eosin (HE) staining and Masson's trichrome staining. Functional myocardial changes were assessed using echocardiography. Our results demonstrated that miR-27a levels were elevated, while H2S levels were reduced in TAC mice and myocardial hypertrophy. Further luciferase and target scan assays confirmed that cystathionine-γ-lyase (CSE) was a direct target of miR-27a and was negatively regulated by it. Notably, enhancement of H2S expression in the heart was observed in mice injected with recombinant adeno-associated virus vector 9 (rAAV9)-anti-miR-27a and in cells transfected with a miR-27a inhibitor during cardiac hypertrophy. However, this effect was abolished by co-transfection with CSE siRNA and the miR-27a inhibitor. Conversely, injecting rAAV9-miR-27a yielded opposite results. Interestingly, our findings demonstrated that glucagon-like peptide-1 (GLP-1) agonists could mitigate myocardial damage by down-regulating miR-27a and up-regulating CSE. In summary, our study suggests that inhibition of miR-27a holds therapeutic promise for the treatment of cardiac hypertrophy by increasing H2S levels. Furthermore, our findings unveil a novel mechanism of GLP-1 agonists involving the miR-27a/H2S pathway in the management of cardiac hypertrophy.

Urinary exosomal microRNA-145-5p and microRNA-27a-3p act as noninvasive diagnostic biomarkers for diabetic kidney disease.

BACKGROUND: Diabetic kidney disease (DKD), characterized by increased urinary microalbumin levels and decreased renal function, is the primary cause of end-stage renal disease. Its pathological mechanisms are complicated and multifactorial; Therefore, sensitive and specific biomarkers are needed. Urinary exosome originate from diverse renal cells in nephron segments and partially mirror the pathological changes in the kidney. The microRNAs (miRNAs) in urinary exosome are remarkably stable and highly tissue-specific for the kidney. AIM: To determine if urinary exosomal miRNAs from diabetic patients can serve as noninvasive biomarkers for early DKD diagnosis. METHODS: Type 2 diabetic mellitus (T2DM) patients were recruited from the Second Hospital of Hebei Medical University and were divided into two groups: DM, diabetic patients without albuminuria [urinary albumin to creatinine ratio (UACR) < 30 mg/g] and DKD, diabetic patients with albuminuria (UACR ≥ 30 mg/g). Healthy subjects were the normal control (NC) group. Urinary exosomal miR-145-5p, miR-27a-3p, and miR-29c-3p, were detected using real-time quantitative polymerase chain reaction. The correlation between exosomal miRNAs and the clinical indexes was evaluated. The diagnostic values of exosomal miR-145-5p and miR-27a-3p in DKD were determined using receiver operating characteristic (ROC) analysis. Biological functions of miR-145-5p were investigated by performing Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. RESULTS: Urinary exosomal expression of miR-145-5p and miR-27a-3p was more upregulated in the DKD group than in the DM group (miR-145-5p: 4.54 ± 1.45 vs 1.95 ± 0.93, P < 0.001; miR-27a-3p: 2.33 ± 0.79 vs 1.71 ± 0.76, P < 0.05) and the NC group (miR-145-5p: 4.54 ± 1.45 vs 1.55 ± 0.83, P < 0.001; miR-27a-3p: 2.33 ± 0.79 vs 1.10 ± 0.51, P < 0.001). The exosomal miR-145-5p and miR-27a-3p positively correlated with albuminuria and serum creatinine and negatively correlated with the estimated glomerular filtration rate. miR-27a-3p was also closely related to blood glucose, glycosylated hemoglobin A1c, and low-density lipoprotein cholesterol. ROC analysis revealed that miR-145-5p had a better area under the curve of 0.88 [95% confidence interval (CI): 0.784-0.985, P < 0.0001] in diagnosing DKD than miR-27a-3p with 0.71 (95%CI: 0.547-0.871, P = 0.0239). Bioinformatics analysis revealed that the target genes of miR-145-5p were located in the actin filament, cytoskeleton, and extracellular exosome and were involved in the pathological processes of DKD, including apoptosis, inflammation, and fibrosis. CONCLUSION: Urinary exosomal miR-145-5p and miR-27a-3p may serve as novel noninvasive diagnostic biomarkers or promising therapeutic targets for DKD.

The diagnostic and prognostic role of miR-27a in cancer.

MicroRNA-27a (miR-27a) has been reported to be abnormally expressed in patients with cancer, and it could play potential roles as a diagnostic and prognostic biomarker of cancers. However, the diagnostic and prognostic role remains unclear. Hence, this meta-analysis, based on published data, was conducted to assess the utility of miR-27a as a diagnostic and prognostic marker in various cancers. To identify eligible studies, databases: Web of Science, PubMed, and CNKI were searched, with 868 literatures obtained, 16 of which were included in the Meta-analysis. The pooled results of studies conducted with serum/plasma showed that miR-27a was a valuable diagnostic biomarker in cancers (area under curve (AUC)= 0.91, sensitivity (SEN)= 0.84, specificity (SPE)= 0.85), with the diagnostic value slightly reduced in tumor tissue samples (AUC=0.83, SEN=0.78, SPE: 0.74). Additionally, the pooled results revealed that high expression of miR-27a predicted poor prognosis of cancer in serum/plasma (hazard ratio (HR) = 0.63, PHeterogeneity = 0.278, I2= 21.50%) but not in tumor tissue (HR = 0.98, PHeterogeneity =0.577, I2= 0.0). In brief, our results suggested that miR-27a in serum/plasma or tumor tissue could act as a diagnostic biomarker, and that miR-27a in serum/plasma could predict cancer patients' survival.

LncRNA DNAJC3-AS1 promotes the biological functions of papillary thyroid carcinoma via regulating the microRNA-27a-3p/CCBE1 axis.

Long noncoding RNA DNAJC3-AS1 (lncRNA DNAJC3-AS1) has been probed in many studies, while the regulatory mechanism of DNAJC3-AS1 on papillary thyroid carcinoma (PTC) via regulating microRNA (miR)-27a-3p remains inadequate. This research aims to depict the role of DNAJC3-AS1, miR-27a-3p, collagen, and calcium-binding EGF domain-containing protein 1 (CCBE1) on PTC development. DNAJC3-AS1, miR-27a-3p, and CCBE1 expression levels in PTC tissues and adjacent normal tissues were tested. The relation of DNAJC3-AS1, miR-27a-3p, and CCBE1 was analyzed. DNAJC3-AS1 and miR-27a-3p and CCBE1-related oligonucleotides were transfected into IHH-4 cells to investigate their role in PTC development. Cell tumorigenicity was detected by in vivo assay. DNAJC3-AS1 and CCBE1 expressed highly and miR-27a-3p expressed lowly in PTC. Downregulation of DNAJC3-AS1, upregulating miR-27a-3p or downregulating CCBE1 impaired the malignant behaviors of IHH-4 cells. Depletion of miR-27a-3p reversed the DNAJC3-AS1 suppression-induced phenotypic inhibition of IHH-4 cells. DNAJC3-AS1 bound to miR-27a-3p and CCBE1 as a target of miR-27a-3p. Our study highlights that DNAJC3-AS1 inhibits miR-27a-3p to promote CCBE1 expression, thereby facilitating PTC development. This study affords distinguished therapeutic strategies and novel research directions for PTC treatment.

Long non-coding RNA PVT1 regulates LPS-induced acute kidney injury in an in vitro model of HK-2 cells by modulating the miR-27a-3p/OXSR1 axis.

Sepsis is a severe inflammatory disease caused by infection that can lead to multiple organ failure. Acute kidney injury (AKI) is considered to be a major cause of septic mortality in infected organs. Previous studies have revealed that non-coding RNAs are involved in AKI, but the underlying mechanisms are mostly unknown. The present study aimed to explore the role of long non-coding RNA plasmacytoma variant translocation gene 1 (lncRNA PVT1) in lipopolysaccharide (LPS)-induced acute kidney injury and the underlying mechanism. In the present study, reverse transcription-quantitative PCR analysis indicated that, in HK-2 cells treated with LPS, the mRNA expression levels of lncRNA PVT1 and oxidative stress responsive kinase 1 (OXSR1) were upregulated, and the expression of microRNA (miR)-27a-3p was downregulated. Furthermore, LPS treatment could promote the secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-6, inhibit cell proliferation and induce apoptosis, which was rescued by PVT1 knockdown. Dual-luciferase reporter assay, RIP assay and pull-down assay results demonstrated that miR-27a-3p may be a target miR of PVT1, and that OXSR1 is the target gene of miR-27a-3p. Moreover, it was found that miR-27a-3p overexpression decreased the secretion of TNF-α and IL-6, promoted cell proliferation and inhibited apoptosis in LPS-treated HK-2 cells, which could be reversed by OXSR1 overexpression. Therefore, the present results indicated that lncRNA PVT1 regulated inflammatory cytokine secretion, cell proliferation and apoptosis by targeting miR-27a-3p, and modulating OXSR1 expression in LPS-induced HK-2 cells.

MicroRNA-27a-5p Inhibits Proliferation, Migration, and Invasion and Promotes Apoptosis of Wilms' Tumor Cell by Targeting PBOV1.

Wilms' tumor is the most common type of renal tumor in children. MicroRNAs (miRNAs) are small noncoding RNAs that play crucial regulatory roles in tumorigenesis. We aimed to study the expression profile and function of miR-27a-5p in Wilms' tumor. miR-27a-5p expression was downregulated in human Wilms' tumor tissues. Functionally, overexpression of miR-27a-5p promoted cell apoptosis of Wilms' tumor cells. Furthermore, upregulated miR-27a-5p delayed xenograft Wilms' tumor tumorigenesis in vivo. Bioinformatics analysis predicted that miR-27a-5p directly targeted the 3'-untranslated region (3'-UTR) of PBOV1, and luciferase reporter assay confirmed the interaction between miR-27a-5p and PBOV1. The function of PBOV1 in Wilms' tumor was evaluated in vitro, and knockdown of PBOV1 dampened cell migration. In addition, overexpression of PBOV1 antagonized the tumor-suppressive effect of miR-27a-5p in Wilms' tumor cells. Collectively, our findings reveal the regulatory axis of miR-27a-5p/PBOV1 in Wilms' tumor, and miR-27a-5p might serve as a novel therapeutic target in Wilms' tumor.

Serum-derived extracellular vesicles mediate Smad4 expression through shuttling microRNA-27a in the progression of laryngeal squamous cell carcinoma.

Serum-derived extracellular vesicles (EVs) containing non-coding RNAs have been indicated to serve as diagnostic and prognostic biomarkers for laryngeal squamous cell carcinoma (LSCC), while their functional role remains to be explored. Here, we summarize the possible mechanism explaining the laryngeal carcinogenesis and the associated changes with the involvement of extracellular microRNA (miR)-27a from serum of LSCC patients. Serum-derived EVs from LSCC patients were found to increase the proliferative activity and decreased the apoptotic activity of LSCC cells. miRNA microarrays revealed that miR-27a expression was elevated after EV treatment. miR-27a expression was elevated in LSCC tissues and predicted a poor prognosis for patients. Downregulation of miR-27a inhibited the effect of EVs to reduce the activity of LSCC cells in vitro and to suppress tumor development in vivo. miR-27a targeted SMAD family member 4 (Smad4) to mediate the Wnt/ß-catenin pathway, which was induced under the influence of EVs. Smad4 was downregulated in LSCC tissues, and simultaneous overexpression of miR-27a and Smad4 resulted in reduced cell activity and tumorigenicity. In conclusion, serum-derived EVs support the laryngeal carcinogenesis at least partially via transferring miR-27a. miR-27a targets Smad4 and is a biomarker to predict LSCC prognosis.

Oxidative stress-related circulating miRNA-27a is a potential biomarker for diagnosis and prognosis in patients with sepsis.

BACKGROUND: Oxidative stress plays a critical role on the processes of sepsis, and several microRNAs have been identified that may regulate the occurrence of oxidative stress. However, the relation between oxidative stress-related microRNA 27a (miR-27a) and sepsis is unknown. The present study aimed to determine the value of circulating miR-27a for the diagnosis and prognosis of sepsis. METHODS: This retrospective study included 23 patients with sepsis and 25 without sepsis treated at the emergency intensive care unit (EICU) or our institution between January 2019 and January 2020. Levels of circulating miR-27a and levels of oxidative stress-related indicators were measured and compared between sepsis and non-sepsis patients. Receiver operating characteristic (ROC) curve analysis was used to determine diagnostic efficiency of miR-27a. RESULTS: Circulating miR-27a levels in sepsis patients were higher than those in non-sepsis patients (p < 0.05), and levels were significantly higher in patients that died than those that lived (p < 0.05). In patients with sepsis, circulating miR-27a level was positively correlated with serum malondialdehyde (MDA) level (rs = 0.529, p = 0.007), and negatively correlated with serum glutathione peroxidase (GSH-Px) level (rs = - 0.477, p = 0.016). No significant correlation was observed between circulating miR-27a and serum superoxide dismutase (SOD) in sepsis patients (rs = - 0.340, p = 0.096). The area under the ROC curve (AUC) of miR-27a level for prediction of sepsis was 0.717 (p = 0.009) and for 28-day mortality was 0.739 (p = 0.003). CONCLUSIONS: This study showed that circulating miR-27a level is correlated with oxidative stress and mortality in patients with sepsis, and may serve as a potential non-invasive molecular biomarker.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Osteoporosis via MicroRNA-27a-Induced Inhibition of DKK2-Mediated Wnt/ß-Catenin Pathway.

Osteoporosis (OP) is a systemic skeletal disease that promotes bone fragility and the risk of fractures. Recent studies have shown the relevance of microRNAs (miRNAs) in the development of OP. This study aimed to evaluate the possible mechanisms of action underlying miR-27a loaded by mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in OP. Serum samples from OP patients and normal controls were collected for miRNA microarray analysis. The expression of filtered miRNA was upregulated in osteoblasts (OB) and osteoclasts (OCs) for biological activity assessment. After developing OP mice using ovariectomy (OVX) and confirming OP, the miR-27a expression level was upregulated in mice by MSC-EV application. Dual-luciferase assays were conducted to validate the relationship between miR-27a and DKK2 expression. The poor expression of miR-27a was observed in patients with OP. miR-27a increased the expression of OB markers, the number of ALP-positive cells, and the number of calcium nodules in OCs. In OVX mice, miR-27a increased bone density, improved bone structure damage recovery, decreased the levels of bone resorption markers, and decreased OC number. miR-27a transmitted by MSC-EVs interacted with DKK2. MSC-EVs exerted the same protective effects as miR-27a on OP, whereas miR-27a inhibitor abolished the attenuating effects of MSC-EVs. In contrast, DKK2 depletion reversed the stimulatory effects of the miR-27a inhibitor on OP. The Wnt/ß-catenin pathway was activated upon MSC-EV application and DKK2 silencing and was impaired upon the downregulation of the expression of miR-27a. MSC-EVs are effective in preventing mouse OP. This mechanism is mediated by the miR-27a/DKK2/Wnt/ß-catenin signaling pathway.

Hepatocyte-derived exosomal miR-27a activateshepatic stellate cells through the inhibitionof PINK1-mediated mitophagy in MAFLD.

The role of exosome-mediated mitophagy in the crosstalk between hepatocytes (HCs) and hepatic stellate cells (HSCs) in metabolic-associated fatty liver disease (MAFLD) remains unknown. Serum exosomal miR-27a levels were markedly increased and positively correlated with liver fibrosis in MAFLD patients and mice. Exosomal miR-27a was released from lipotoxic HCs and specifically transmitted to recipient-activated HSCs. PINK1, the key target of miR-27a, primarily mediates mitophagy. Overexpression of miR-27a or knockdown of PINK1 or lipotoxic HC-exosomal miR-27a impaired mitochondria (inhibiting mitophagy, respiration, membrane potential, and transcription while promoting reactive oxygen species production) in activated HSCs and stimulated HSC-derived fibroblasts (promoting activation and proliferation while inhibiting autophagy). High exosomal miR-27a serum levels and a lack of hepatic PINK1-mediated mitophagy were directly related to liver fibrosis in MAFLD mice. Lipotoxic HC exosome transplantation aggravated the degree of PINK1-mediated mitophagy suppression, steatohepatitis, lipidosis, and fibrosis in the livers of MAFLD mice with cirrhosis. Both in vitro and in vivo, exosomes derived from miR-27a-knockdown HCs could not facilitate the abovementioned deteriorating effects. In conclusion, lipotoxic HC-exosomal miR-27a plays a pivotal role in inhibiting mitophagy and in promoting MAFLD-related liver fibrosis by negatively regulating PINK1 expression.

microRNA-27a-3p but Not -5p Is a Crucial Mediator of Human Adipogenesis.

MicroRNAs (miRNAs), a class of small, non-coding RNA molecules, play an important role in the posttranscriptional regulation of gene expression, thereby influencing important cellular functions. In adipocytes, miRNAs show import regulatory features and are described to influence differentiation as well as metabolic, endocrine, and inflammatory functions. We previously identified miR-27a being upregulated under inflammatory conditions in human adipocytes and aimed to elucidate its function in adipocyte biology. Both strands of miR-27a, miR-27a-3p and -5p, were downregulated during the adipogenic differentiation of Simpson-Golabi-Behmel syndrome (SGBS) cells, human multipotent adipose-derived stem cells (hMADS), and human primary adipose-derived stromal cells (hASCs). Using miRNA-mimic transfection, we observed that miR-27a-3p is a crucial regulator of adipogenesis, while miR-27a-5p did not alter the differentiation capacity in SGBS cells. In silico screening predicted lipoprotein lipase (LPL) and peroxisome proliferator activated receptor γ (PPARγ) as potential targets of miR-27a-3p. The downregulation of both genes was verified in vitro, and the interaction of miR-27-3p with target sites in the 3' UTRs of both genes was confirmed via a miRNA-reporter-gene assay. Here, the knockdown of LPL did not interfere with adipogenic differentiation, while PPARγ knockdown decreased adipogenesis significantly, suggesting that miR-27-3p exerts its inhibitory effect on adipogenesis by repressing PPARγ. Taken together, we identified and validated a crucial role for miR-27a-3p in human adipogenesis played by targeting the essential adipogenic transcription factor PPARγ. Though we confirmed LPL as an additional target of miR-27a-3p, it does not appear to be involved in regulating human adipogenesis. Thereby, our findings call the conclusions drawn from previous studies, which identified LPL as a crucial regulator for murine and human adipogenesis, into question.

Long non­coding RNA XIST promotes cerebral ischemia/reperfusion injury by modulating miR­27a­3p/FOXO3 signaling.

Cerebral ischemia/reperfusion (I/R) injury leads to neuronal damage, which may cause disability and even mortality. Multiple studies have revealed that long non­coding RNAs (lncRNAs) serve pivotal roles in the pathogenesis of cerebral I/R injury. Therefore, the present study aimed to investigate whether the lncRNA X inactivate­specific transcript (XIST) protects neuronal cells from cerebral I/R injury. In the present study, reverse transcription­quantitative PCR demonstrated that XIST expression was upregulated in the brain tissues of an I/R mouse model and in oxygen and glucose deprivation/reperfusion (OGD/R)­treated Neuro­2a (N2a) cells. Knockdown of XIST alleviated cerebral injury, as well as reduced N2a cell apoptosis and reactive oxygen species (ROS) production. Additionally, luciferase reporter and RNA immunoprecipitation assays identified that XIST could bind with microRNA (miR)­27a­3p. It was found that miR­27a­3p expression was downregulated in the brain tissues of an I/R mouse model and in OGD/R­induced N2a cells. In addition, miR­27a­3p overexpression attenuated I/R­induced cerebral injury, and inhibited the apoptosis and ROS production of N2a cells. miR­27a­3p was found to target FOXO3. Silencing of FOXO3 alleviated cerebral injury, as well as inhibited N2a cell apoptosis and ROS production. Collectively, these findings indicated that XIST aggravated cerebral I/R injury by regulating miR­27a­3p/FOXO3 signaling, which may provide a novel insight into the treatment of cerebral I/R injury.

The Influence of Bosentan on MicroRNA-27a/PPARγ/ET-1 Signaling Pathway in Pulmonary Artery Hypertension.

Pulmonary artery hypertension (PAH) is a common and serious disease which is characterized by pulmonary vascular remodeling. Bosentan (BST) is the first approved oral targeted drug of endothelin-1 (ET-1) receptor antagonists for the treatment of PAH. MicroRNA-27a (miR-27a) and peroxisome proliferator-activated receptor γ (PPARγ) were found to be related to the pathogenesis of PAH. To further explore the signal transduction mechanism of BST in the treatment of PAH, we examined the effects of BST on endothelin receptors, miR-27a, and PPARγ. Meanwhile, the influence of miR-27a in the formation and development of PAH was discussed. Our results demonstrated that during the pathophysiology of PAH, miR-27a, PPARγ, and ET-1 were cross-inhibited, which indicated that the miR-27a/PPARγ/ET-1 signaling pathway was dysregulated; in addition, BST could competitively bind to ET-1 receptors and inhibit the miR-27a/PPARγ/ET-1 signaling pathway, thereby delaying the proliferation of PASMCs and affecting the development of PAH. Our results give a new understanding of the pathogenesis and treatment of PAH and provide more reliable evidence for the application of BST in the treatment of PAH in the clinic.

Oncogenic miR-27a delivered by exosomes binds to SFRP1 and promotes angiogenesis in renal clear cell carcinoma.

Exosomes derived from cancer cells have emerged as important mediators of malignant phenotypes of tumors, being involved in the transmission of biological signals between cells. Herein, we intended to clarify the role of exosome-mediated transfer of oncogenic microRNA-27a (miR-27a) in angiogenesis of renal clear cell carcinoma (RCCC). Through bioinformatics analysis, we identified the differentially expressed genes of RCCC and predicted miRNAs targeting SFRP1. We manipulated the expression of miR-27a and/or SFRP1 in RCCC cells to explore their roles in angiogenesis through Cell Counting Kit-8 (CCK-8), Transwell, and Matrigel tubule formation assays. miR-27a loaded in exosomes was overexpressed and downregulated in vitro and in vivo to verify its effect on angiogenesis. SFRP1 was poorly expressed and miR-27a was highly expressed in RCCC tissues, showing a negative correlation. Dual-luciferase assay verified that miR-27a targeted and downregulated SFRP1 expression. Notably, miR-27a enhanced angiogenesis by downregulating SFRP1 expression. miR-27a-loaded exosomes can be delivered from RCCC cells to human umbilical vein endothelial cells (HUVECs). In vitro and in vivo experiments substantiated that miR-27a-loaded exosomes from RCCC cells repressed SFRP1, augmenting the viability, migration, and angiogenesis of RCCC cells. Together, RCCC-derived miR-27a-loaded exosomes inhibit SFRP1 expression and accelerate tumor angiogenesis in RCCC.

Radio-sensitizing effects of microRNA-27a elevation in lung cancer cells by inhibiting ZEB1 expression and activating DNA damage repair pathway.

MicroRNAs (miRNAs or miRs) exert either as tumor-inhibiting or oncogenic roles in tumorigenesis of lung cancer. In the present study, we identified a novel microRNA (miR)-27a as being involved in the radiosensitivity of lung cancer cells. Therefore, we sought to characterize its potential underlying mechanism in lung cancer cell sensitivity to radiotherapy. To this end, A549 and H460 cells irradiated with 8 Gy irradiation (IR) were used as a cell model. RT-qPCR exhibited that the expression of miR-27a increased, whereas ZEB1 was poorly expressed in A549 and H460 cells exposed to IR. As reflected by dual-luciferase reporter gene assay, miR-27a could target and inversely modulate ZEB1 expression. Gain- and loss-of-function experiments exhibited that miR-27 inhibition promoted proliferation of IR-treated A549 and H460 cells and reduced the sensitivity of A549 and H460 cells to radiotherapy, which was rescued by silencing of ZEB1. Further, miR-27a inhibition disrupted the homologous recombination (HR)-mediated DNA repair, evidenced by reduced ATM, pCHK2 and Rad51 levels. Collectively, miR-27a activates HR-mediated DNA repair by inhibiting ZEB1 expression to enhance the radiosensitivity of lung cancer cells, highlighting a therapeutic target for lung cancer radiosensitivity.

Overexpression of miR-27a predicts poor prognosis and promotes the progression in cholangiocarcinoma.

The function of microRNA-27a (miR-27a) expression in cholangiocarcinoma (CCA) remains largely unclear; therefore, this study aimed to investigate the clinical significance and functional role of miR-27a in CCA. This study included 117 paired CCA tissues and adjacent normal tissues from CCA patients who received surgical resection. Reverse transcription-quantitative polymerase chain reaction was used to measure the expression levels of miR-27a in CCA tissues and cell lines. A Kaplan-Meier curve and Cox regression analysis were used to determine overall prognostic performance. The effects of miR-27a on cell proliferation, migration, and invasion were measured by CCK-8 and Transwell assays. The expression levels of miR-27a in patients with CCA and cell lines were higher than those in adjacent normal tissues and normal cells, respectively. Additionally, miR-27a levels were found to be associated with lymph node metastasis and TNM stages. The overall survival time of CCA patients with high miR-27a expression was poorer than that of those with low miR-27a expression. Furthermore, miR-27a overexpression promoted CCA cell proliferation, migration, and invasion, whereas knockdown of miR-27a suppressed cell proliferation, migration, and invasion. Taken together, these results suggest the potential usefulness of miR-27a in the prognosis and progression of CCA.

Expressions of miR-27a and NRF2 in serum of patients with age-related macular degeneration bleeding and their prognostic correlation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To detect the relative expression levels of microRNA-27a(miR-27a)and nuclear factor erythroid-2-related factor 2(NRF2)in serum of patients with age-related macular degeneration(ARMD)bleeding, and to explore the correlation between the expression levels and the prognosis of ARMD bleeding. <p>METHODS: A retrospective case series observation was carried out.From June 2018 to October 2019, 80 patients with ARMD bleeding who were treated in our hospital were selected as ARMD bleeding group, and 80 healthy people who had routine examination in our hospital were selected as control group. The relative expression levels of miR-27a and NRF2 were detected by real-time fluorescent quantitative PCR(qRT-PCR), the diagnostic value of serum miR-27a and NRF2 expression for ARMD bleeding was evaluated by receiver operating characteristic curve(ROC). The incidence of poor prognosis was analyzed; in addition, Logistic regression was used to analyze the influencing factors of poor prognosis in patients with ARMD bleeding. <p>RESULTS: The relative expression level of miR-27a in serum of ARMD bleeding group was significantly higher than that of control group(<i>P</i><0.01), and the relative expression level of NRF2 mRNA in serum was significantly lower than that in control group(<i>P</i><0.01). ROC results showed that the AUC of serum miR-27a and NRF2 in the diagnosis of ARMD bleeding was 0.867 and 0.820 respectively, and the cutoff value was 1.10 and 1.08 respectively, at this time, the corresponding sensitivity was 71.3% and 91.3%, and the specificity was 90.0% and 63.7%, respectively. The AUC of serum miR-27a combined with NRF2 in the diagnosis of ARMD bleeding was 0.912, and the corresponding sensitivity and specificity were 86.3% and 85.0%, respectively. The incidence of poor prognosis in high miR-27a group was significantly higher than that in low miR-27a group(<i>P</i><0.05); and the incidence of poor prognosis in high NRF2 group was significantly lower than that in low NRF2 group(<i>P</i><0.05). Logistic analysis showed that the high expression of serum miR-27a was an independent risk factor for poor prognosis in patients with ARMD bleeding, and the high relative expression of NRF2 in serum was a protective factor for the poor prognosis of patients with ARMD bleeding. <p>CONCLUSION: The relative expression level of miR-27a in the serum of patients with ARMD hemorrhage is significantly increased, and the relative expression level of NRF2 is significantly decreased, both of them have certain diagnostic value for ARMD bleeding, and their relative expressions are closely related to the prognosis of patients, which is suggested that miR-27a and NRF2 can be used as potential biological indexes for early diagnosis and prognosis evaluation of ARMD bleeding.

FBLN5 is targeted by microRNA­27a­3p and suppresses tumorigenesis and progression in high­grade serous ovarian carcinoma.

High-grade serous ovarian carcinoma (HGSOC) is one of the most lethal gynecological malignancies; however, the precise molecular mechanisms have not been fully characterized. Fibulin­5 (FBLN­5) is an extracellular matrix (ECM) glycoprotein, and plays a crucial role in maintaining the stability of ECM structures, regulating cell proliferation and tumorigenesis. In the present study, the expression of FBLN­5, as determined by western blot analysis and immunohistochemistry, was significantly increased in normal fallopian tube (FT) samples compared with that in HGSOC samples, and decreased FBLN5 expression was associated with unfavorable prognosis of HGSOC. Functional characterization revealed that FBLN5 overexpression significantly inhibited migration, invasion and proliferation abilities of ovarian cancer cells in vitro. Furthermore, micro (mi)RNA­27a­3p (miR­27a­3p) was revealed to be increased in HGSOC, and dual­luciferase reporter assay indicated that miR­27a­3p was functioned as a negative regulator of FBLN5 by directly binding with its 3'­untranslated region. Collectively, FBLN5 expression was associated with prognosis, proliferation, and metastasis in HGSOC. We hypothesized that FBLN5 was targeted by miR­27a­3p and may serve as a biomarker and provide a new therapeutic approach for the treatment of HGSOC.

Endoplasmic reticulum stress-induced exosomal miR-27a-3p promotes immune escape in breast cancer via regulating PD-L1 expression in macrophages.

Immune escape of breast cancer cells contributes to breast cancer pathogenesis. Tumour microenvironment stresses that disrupt protein homeostasis can produce endoplasmic reticulum (ER) stress. The miRNA-mediated translational repression of mRNAs has been extensively studied in regulating immune escape and ER stress in human cancers. In this study, we identified a novel microRNA (miR)-27a-3p and investigated its mechanistic role in promoting immune evasion. The binding affinity between miR-27a-3p and MAGI2 was predicted using bioinformatic analysis and verified by dual-luciferase reporter assay. Ectopic expression and inhibition of miR-27a-3p in breast cancer cells were achieved by transduction with mimics and inhibitors. Besides, artificial modulation of MAGI2 and PTEN was done to explore their function in ER stress and immune escape of cancer cells. Of note, exosomes were derived from cancer cells and co-cultured with macrophages for mechanistic studies. The experimental data suggested that ER stress biomarkers including GRP78, PERK, ATF6, IRE1α and PD-L1 were overexpressed in breast cancer tissues relative to paracancerous tissues. Endoplasmic reticulum stress promoted exosome secretion and elevated exosomal miR-27a-3p expression. Elevation of miR-27a-3p and PD-L1 levels in macrophages was observed in response to exosomes-overexpressing miR-27a-3p in vivo and in vitro. miR-27a-3p could target and negatively regulate MAGI2, while MAGI2 down-regulated PD-L1 by up-regulating PTEN to inactivate PI3K/AKT signalling pathway. Less CD4+ , CD8+ T cells and IL-2, and T cells apoptosis were observed in response to co-culture of macrophages and CD3+ T cells. Conjointly, exosomal miR-27a-3p promotes immune evasion by up-regulating PD-L1 via MAGI2/PTEN/PI3K axis in breast cancer.